Back connected switch terminal



Nov. 28, 1933- E. c. OTTE BACK CONNECTED SWITCH TERMINAL Filed July 25, 1930 Fig. 3

Patented Nov. 28, 1933 PATENT OFFICE BACK CONNECTED SWITCH TERMINAL Emil C. Otte, Chicago, Ill., assignor to The Delta- Star Electric Company, Chicago, Ill., a corporation of Illinois Application July 23, 1930. Serial No. 470,064

6 Claims.

This invention relates to back connected switch terminals having a structure in which the terminal may be made of tubing and formed to be supported in a suitable manner so that the terminals will support and contact with the switch blades. This switch stud or terminal provides a strong mounting for the switch blades which may be very economically manufactured and which overcomes undesirable features in the manufacture of switches where it is necessary to rivet and sweat the parts together in conjunction with the cast parts which make up the switch terminals and switch blade supports. The economical structure accomplished by this terl5-minal construction is a material advantage in the making ofswitches.

It is also a feature of these switch terminals to provide a terminal for the switch which has the advantage of heat radiation, stronger terminal support, and ease of manufacture and assembly.

A terminal made of tubing with one end flattened to connect with the switch blades provides a better electrical conductor owing to its integral construction and formation than where the'terminal is made of several cast pieces sweated or connected together.

These terminals may be used in various ways to support the switch blades and may be mounted with an insulator extended over the body of each terminal and clamped thereto or with the tubular terminal extending through a supporting base and with insulators on either side of the base.

I The features of the terminal and switch structure will be fully and clearly set forth.

In the drawing which forms a part of this specification:

Figure 1 is a side view of a switch supported I I by the new type of terminals.

- Figure 2 illustrates an enlarged view of one of the terminals mounted upon an insulator.

Figure 3 is a plan view of Figure 2. Figure 4 illustrates another form of my terminal.

' Figure 5 is a cross section switch blade terminal.

The terminals A and B which support the parallel switch blades 10 are formed of a metal I tubing and may be of any suitable size and thick- -ness so as to provide the desired support for the switch blades.

The switch terminals A and B are of the same nature in that they are formed of tubing, the terminal A being used to hingedly connect the parallel switch blades 10 and the terminal B of a form of my to act as the contact terminal for the free end of the switch blades. The terminals A and B are made by flattening one end of the same to form the contact portion with the switch blades, such as 11. The tubular body portion 12 of the 60. terminals is hollow and may be threaded from the opposite end to the flattened portion to a point adjacent to the flattened portion 11, such as is illustrated by the threads 13 in Figure 2. In this construction the tubular terminal B carries an insulator C which is held between the nuts 14 and 15 on the threaded body of the terminal.

The terminals A and B in Figure 1 may be of the same structure as that illustrated in Figure 2, where they are formed with the threaded portion 13. In this structure the upper lock nuts 14 engage against the upper insulators C which bear against the supporting base 16. Below the supporting base 16 lower supporting insulators 75. C are provided and these are held by the lower lock nuts 15.

Thus in Figure l I have illustrated the switch blades 10 supported to the terminals A and B and the terminals supported bythe base plate 16 80. with a pair of insulators on either side of the plate. The structure is the same as in Figure 2 excepting one insulator is used on the body of the terminal in Figure 2, while two insulators are used on the body of the terminals in Figure l. The terminals in Figure I extend through the plate or base 16 and the insulators C are adapted to support the terminals from the base 16, the opening through the base being long enough so that the terminals will not contact with the base. The lock nuts 14 and 15 hold the terminals A or B rigidly in place.

The terminals A and B may be made as illustrated in Figure 4 with both ends flattened at 17 similarly to the flattening of the end 11 and in this construction the body of the terminal is not threaded but I provide clamping collars 18 which extend around the body or shank of the terminal at either end of the insulator C to hold the insulator on the terminal. The insulator may be divided as in Figure 1, into two parts if it is de- 0 sired. The clamping members 18 rigidly clamp about the tubular body of the terminal so as to hold the terminal and insulator in firm relation to each other.

A tubular switch terminal formed in a single 1 5 piece with one end flattened so as to receive and contact with the switch blades provides a very eflicient switch blade supporting means and conductor for the current. Not only does this form of terminal accomplish greater efiiciency than 0 structures used heretofore, but it also has the advantage of economy and ease of assembly. If it is not desirable to thread the body like in Figures 1 and 2, then the switch terminal may be held by the clamping collars 18. Where both ends of the terminal are flattened, one flattened end may be provided with holes such as 20, so that an electrical conductor may be attached thereto, or one of the holes may be used in the supporting of the i terminal while the other is used for an electrical connection. It is an easy matter to form these terminals as it is only necessary to flatten the ends, such as 11, to provide a contacting portion for the switch blades 10. The switch blades may be hingedly connected at 21 to one of the flattened surfaces 11 to the terminal, such as A.

The switch terminals A or B may be made with one or more openings such as 24 illustrated in dotted outline in Figure 2 to permit an air draft through the hollow body of the terminal'for cooling the same in operation of the switch. In Figure 5 I have illustrated a hollow switch blade terminal A. In this construction, the flattened end 11 does not have the side walls or" the tube fiat- 203 tened together so as to close one end of the terminal, but are spaced apart to provide an air passageway 25. This construction permits the air to pass through the enlarged tubular passageway 26 in the body portion 12 and through the air 30? passageway 25 in the flattened portion 11 so that a free circulation of air may pass straight through the entire terminal A for the purpose of keeping the terminal cool when the switch is carrying a heavy load. My terminals are more efficient 36T owing to their integral tubular nature and the advantage of cooling the surface by spreading the same out to a larger contact with the air, and in their hollow nature they permit the free circulation of air over a large portion of the area of 40' the terminal, thus being very efficient in use. The terminals are made of copper or other suitable material having a high electrical conductivity. They are sturdy and provide a better electrical connection than where terminals are made of sevill v eral pieces and sweat together. The cooling of the terminals is important in a switch as it provides for greater efiiciency.

The invention has been set forth and described in accordance with the patent statutes and while a particular formation and construction has been set forth, it is apparent that obvious variations and formations may be made in the form of the tubular terminals and when the same are accomplished within the scope of the following claims they should be considered as a part of this invention as if they had been mentioned in each and every part thereof.

I claim:

1'. The combination, switch blades, a pair of tubular switch blade'terminals having a straight integral formation from end to end, flattened switch blade hinge and contact portions, ventilating spaces between the sides of said flattened portions, and rigid insulator and clamping means for clamping said insulators on said terminals for supporting said terminals to provide an electrical switch with high electrical conductivity terminal posts.

2. The combination, switch blades, tubular terminals for said blades having a high electrical conductivity, flattened connecting portions and an air passage through said terminals from end to end adapted to tend to cool the same.

3. A tubular switch blade terminal having a hollow body portion, a flattened end engaged on the outside by the switch blade, and an air passageway through said terminal from end to end to tend to cool the same under electrical load.

4. A switch terminal including, a tubular body, a flattened end thereupon, a ventilating passage through said body, and a continuation of said passage through said flattened end.

5. A switch terminal including, a tubular body, a switch blade connecting end formed by squeezing the sides of one end of the tube together, the flattened sides extending in parallel relationship and spaced slightly apart to provide a ventilating passage between'the same.

6. A ventilated switch terminal including, a. tubular member, flattened ends thereupon, and a ventilating passage extending through said tubular member and flattened ends.

EMIL C. OTTE. 

